Dynamic Liquid Measurement Calculations

Scott Tanner Flow-Cal, Inc.

Chapter 12 - Calculation of Petroleum Quantities

Section 1 Calculation of Static Petroleum Quantities

Section 2 Calculation of Petroleum Quantities Using Dynamic Measurement Methods and Volumetric Correction Factors

Section 3 Calculation of Volumetric Shrinkage from Blending Light Hydrocarbons with Crude Oil

Chapter 12.2 Organization

Part 1 Introduction Part 2 Measurement Tickets Part 3 Proving Reports Part 4 Calculation of Base Prover

Volumes by the Waterdraw Method Part 5 Calculation of Base Prover

Volume by Master Meter Method

Chapter 12.2.x Applicable Liquids

Hydrocarbon Liquids Which are Considered to be Clean Single-Phase Homogeneous Newtonian at Metering Conditions

Chapter 12.2.x Density Types

Base or Standard Condition Observed Condition Alternate Conditions

Distinction Between Base and Standard Condition

Base or Standard Condition is a defined temperature and pressure at which liquid volumes are corrected for custody transfer purposes. The terms Base and Standard are used

interchangeably.

Chapter 12.2.x Base Conditions United States Customary (USC) Units:

Temperature (Tb): 60.0F (15.56C) Pressure (Pb): 14.696 psia (101.325 kPaa)

International System (SI) Units: Temperature (Tb): 15.0C (59.0F) or 20.0C (68.0F) Pressure (Pb): 101.325 kPaa (14.696 psia)

For Liquids with an Equilibrium Vapor Pressure (EVP) > Base Pressure (Pb), the (Pb) shall be the EVP at Base Temperature (Tb)

Distinction Between Observed, and Alternate Conditions

Observed Condition is the temperature and

pressure at which the density of a liquid is actually measured Density Meter or Hydrometer Condition

Alternate Conditions are any other temperature and pressure conditions to which the observed or standard density can be corrected Metering or Tank Condition

Commodity Types A = Crude Oil B = Refine Product C = Special Application D = Lubricating Oil

API Chapter 11.1 uses Three Distinct Calculation Types

Type 1. Starts with Base density and corrects it to an alternate temperature and pressure condition using CTL & CPL Procedures:

11.1.6.1 (USC) & 11.1.7.1 (SI) Functions:

densA11161API & densA1161RelDens ctplB11161API & ctplB11161RelDens fpC11161API & fpC11161RelDens densD11171kPa & densD1171Bar ctplA11171kPa & ctplA11171Bar fpB11171kPa & fpB11171Bar

API Chapter 11.1 uses Three Distinct Calculation Types

Type 2. Starts with Observed density at its temperature & pressure and corrects it to base condition using CTL & CPL Procedures:

11.1.6.2 (USC) & 11.1.7.2 (SI) Functions:

densB11162API & densB1162RelDens ctplC11162API & ctplC11162RelDens fpD11162API & fpD11162RelDens densA11172kPa & densA1172Bar ctplB11172kPa & ctplB11172Bar fpC11172kPa & fpC11172Bar

API Chapter 11.1 uses Three Distinct Calculation Types

Type 3. Starts with Observed density at its temperature & pressure and corrects it to an Alternate temperature & pressure condition Procedures:

11.1.6.3 (USC) & 11.1.7.3 (SI) Functions:

densA11162API > ctplA11161API densB11162RelDens > ctplB11161RelDens dens1C1162API > fpC11161API densD11172kPa > ctplD11171kPa densA11172Bar > ctplA11171Bar densC11172kPa > fpC11161kPa

Chapter 12.2.x Step 1 Determine Base Density (RHOb)

Use an API 11.1 Type 2 Density Calculation API 11.1 Procedure 11.1.6.2 for USC Unit API 11.1 Procedure 11.1.7.2 for SI Units

Enter Observed density at its observed temperature and pressure RHOobs (XXX.x API, X.xxx5 RD or XXXX.5 kg/m3) Tobs ( XXX.x F or XX.x5 C) Pobs (XXXX.0 psig or XX.xxx bar or XXXX.0 kPa) Tb (15.0 or 20.0C for SI Units only)

Determine Base Density (RHOb)

Chapter 12.2.x Step 2 Are the Meter Readings Temperature Compensated?

If Yes Go To Step 3a If No Go To Step 3b

Chapter 12.2.x Step 3a Determine Temperature Correction Factor (CTL) Set CTL = 1.0000

Chapter 12.2.x Step 3b Determine Temperature Correction Factor (CTL) Use an API 11.1 Type 1 Calculation

API 11.1 Procedure 11.1.6.1 for USC Unit API 11.1 Procedure 11.1.7.1 for SI Units

Enter the base density at the meters flow weighted temperature and pressure RHOb (XXX.x API, X.xxxx RD or XXXX.x kg/m3) from Step 1 TWA ( XXX.x F or XX.x5 C) PWA (XXXX.0 psig or XX.xxx bar or XXXX.0

kPa) Tb (15.0 or 20.0C for SI Units only)

Determine CTL

Chapter 12.2.x Step 4 Are Meter Readings Pressure Compensated?

If Yes Step 5a If No Step 5b & 5c

Chapter 12.2.x Step 5a Determine Pressure Correction Factor (CPL)

Set CPL = 1.0000

Chapter 12.2.x Step 5b Determine Scaled Compressibility Factor (Fp)

Use an API 11.1 Type 1 calculation API 11.1 Procedure 11.1.6.1 for USC Unit API 11.1 Procedure 11.1.7.1 for SI Units

Enter the base density at the meters flow weighted temperature and pressure RHOb (XXX.x API, X.xxxx RD or XXXX.x kg/m3) TWA ( XXX.x F or XX.x5 C) PWA (XXXX.0 psig or XX.xxx bar or XXXX.0 kPa) Tb (15.0 or 20.0C for SI Units only)

Step 5b Determine F

Where: = Base Density T = Flow Weighted Temperature

( )2

79320.0 2326.0*exp 1.9947 0.00013427

TF

+ = + +

Determine Fp

Chapter 12.2.x Step 5c Determine CPL

Use an API 11.1 Type 1 calculation API 11.1 Procedure 11.1.6.1 for USC Unit API 11.1 Procedure 11.1.7.1 for SI Units

Enter the base density at the meters flow weighted temperature and pressure RHOb (XXX.x API, X.xxxx RD or XXXX.x kg/m3) TWA ( XXX.x F or XX.x5 C) from Step 1 PWA (XXXX.0 psig or XX.xxx bar or XXXX.0 kPa) Tb (15.0 or 20.0C for SI Units only)

Step 5c Determine CPL

Where: F = Scaled Compressibility Factor PWA = Flow Weighted Pressure Pe = Equilibrium Vapor Pressure

( )51

1 10 * * eCPL

F PWA P=

Determine CPL

Chapter 12.2.x Step 6 Determine Combined Correction Factor (CCF)

CCF = (CTL) * (CPL) * (MF) X.xxxx If a Meter Factor (MF) is Used

CCF = (CTL) * (1.0000) * (CMF) X.xxxx If a Composite Meter Factor (CMF) is Used

CCF = (CTL) * (CPL) * (1.0000) X.xxxx If an Actual K-Factor (KF) is used

CCF = (CTL) * (1.0000) * (1.0000) X.xxxx If a Composite K-Factor (CKF) is used

Determine CCF

Chapter 12.2.x Step 7 Determine Indicated Volume (IV)

IV = MRc MRo Barrels & Gallons = XXX.xx Cubic Meter = XXX.xxx Liter = XXX.0

where: IV = Indicated Volume MRc = Meter Reading Closed MRo = Meter Reading Opened

Determine Indicated Volume (IV)

Chapter 12.2.x Step 8 Determine Gross Standard Volume (GSV)

GSV = IV * CCF Barrels & Gallons = XXX.xx Cubic Meter = XXX.xxx Liter = XXX.0

where: GSV = Gross Standard Volume IV = Indicated Volume (Step 7) CCF = Combined Correction Factor (Step 6)

Determine GSV

Chapter 12.2.x Step 9 Determine Sediment & Water Correction Factor

where: CSW = Correction for Sediment and Water %S&W = Sediment and Water Percent

1 (% & /100)CSW S W=

Determine CSW

Chapter 12.2.x Step 10 Determine Net Standard Volume (NSV)

NSV = GSV * CSW Barrels & Gallons = XXX.xx Cubic Meter = XXX.xxx Liter = XXX.0

where: NSV = Net Standard Volume GSV = Gross Standard Volume (Step 8) CSW = Sediment & Water Correction Factor (Step 9)

Determine NSV

Chapter 12.2.x Step 11 Determine Sediment & Water Volume (SWV)

SWV = GSV - NSW Barrels & Gallons = XXX.xx Cubic Meter = XXX.xxx Liter = XXX.0

where: SWV = Sediment and Water Volume NSV = Net Standard Volume (Step 10) GSV = Gross Standard Volume (Step 8)

Determine SWV

Dynamic Liquid Measurement CalculationsChapter 12 - Calculation of Petroleum QuantitiesChapter 12.2 OrganizationChapter 12.2.x Applicable LiquidsChapter 12.2.x Density TypesDistinction Between Base and Standard ConditionChapter 12.2.x Base ConditionsDistinction Between Observed, and Alternate Conditions Commodity TypesAPI Chapter 11.1 uses Three Distinct Calculation TypesAPI Chapter 11.1 uses Three Distinct Calculation TypesAPI Chapter 11.1 uses Three Distinct Calculation TypesSlide Number 13Chapter 12.2.x Step 1 Determine Base Density (RHOb)Determine Base Density (RHOb)Chapter 12.2.x Step 2 Are the Meter Readings Temperature Compensated?Chapter 12.2.x Step 3a Determine Temperature Correction Factor (CTL)Chapter 12.2.x Step 3b Determine Temperature Correction Factor (CTL)Determine CTLChapter 12.2.x Step 4 Are Meter Readings Pressure Compensated?Chapter 12.2.x Step 5a Determine Pressure Correction Factor (CPL)Chapter 12.2.x Step 5b Determine Scaled Compressibility Factor (Fp)Step 5b Determine FDetermine FpChapter 12.2.x Step 5c Determine CPLStep 5c Determine CPLDetermine CPLChapter 12.2.x Step 6 Determine Combined Correction Factor (CCF)Determine CCFChapter 12.2.x Step 7 Determine Indicated Volume (IV) Determine Indicated Volume (IV)Chapter 12.2.x Step 8 Determine Gross Standard Volume (GSV)Determine GSVChapter 12.2.x Step 9 Determine Sediment & Water Correction FactorDetermine CSWChapter 12.2.x Step 10 Determine Net Standard Volume (NSV)Determine NSVChapter 12.2.x Step 11 Determine Sediment & Water Volume (SWV)Determine SWVSlide Number 40